Properties of covalent compounds
Covalent compounds have several properties that distinguish them from ionic compounds and metals. These properties are:
The melting and boiling points of covalent compounds are generally lower than those of ionic compounds.
Covalent compounds are generally more flexible than ionic compounds. The molecules in covalent compounds are able to move around to some extent and can sometimes slide over each other (as is the case with graphite, which is why the lead in your pencil feels slightly slippery). In ionic compounds, all the ions are tightly held in place.
Covalent compounds generally do not conduct electricity when dissolved in water, for example iodine dissolved in pure water does not conduct electricity.